"Keep clear documentation of the order and payment process, such as e-mails, SMS alerts or even screenshots of the payment made to facilitate dispute resolution," said Mr Seah.

He also advised using a postal service that offers parcel tracking, especially if you are buying a high-value item.

Something is wrong with your item?

Under the lemon law in Singapore, which falls under the Consumer Protection (Fair Trading) Act and applies to goods and services sold online by a registered Singapore company, buyers can make a claim for a defective product within six months of purchase.

You can request for repair, replacement, reduction in price or a refund, said Mr Seah.

"However, if the seller is based overseas, the laws applicable in other countries may differ from those in Singapore and achieving recourse is time-consuming, expensive and difficult," he added.

If you're required to pay a deposit for the item, always negotiate to pay a small amount. Case executive director Seah Seng Choon

There are also some exceptions to the law.

For example, it does not cover consumer-to-consumer transactions, and does not apply if the damage was caused by wear and tear instead of an inherent defect.

The seller asks for a deposit?

With consumer-to-consumer shopping apps such as Carousell, say no to paying in full before you receive your purchase.

This will help prevent you from losing your money to scammers or having your credit card details used for unscrupulous purposes.

"If you're required to pay a deposit for the item, always negotiate to pay a small amount," said Mr Seah.

"Arrange to pay the full amount only after the goods are in your hands and in good order."

The police also warn that some scammers may use a local bank account for the transaction to enhance their credibility.

It advises against providing information that is not necessary to make the purchase, and to never give your bank account and credit card numbers to anyone you have not checked out.

If advance payments are necessary, insist on getting a contact number so the seller's identity can be verified.

You have problems returning the product?

Certain e-commerce platforms will cover the shipment cost for returns or offer a replacement if there is a valid reason, such as damaged or defective goods, said Mr Seah.

However, this is not always the case, so read the fine print before buying.

Some retailers may state that goods can only be refunded or exchanged within a certain period of time, and that the seller is responsible for shipping charges. Or they may have a no exchange, no refund policy.

Mr Seah said: "If consumers are not satisfied with the return or exchange policy, they may wish to buy from a different seller instead."

These articles are adapted from Simply Her. Simply Her is now available in both print and digital formats. Go to www.simplyher.com.sg to subscribe.

Don't shop on public computers

Here is what Mr David Freer, vice-president of Consumer Asia Pacific at Intel Security, says you need to do.

Read the company's privacy policy

Check how the merchant uses your personal data and check that it will not be shared with third parties.

Do not use a public computer

Computers save or cache information such as your login details, and if you use a public omputer, strangers using it after you will be able to access that information.